1. Technical Field of the Invention
The invention relates to a vehicle jack, applicable especially to jacks of the type known as Y-jacks, which is composed of a base to act as a support on the ground, a first member or body which is connected to the said base body and rotates on it; a second member or arm that rotates on the body; a threaded screw spindle that connects together the body and the arm and which is operated by a winding handle.
The upper end of the body receives a nut through which the threaded screw spindle passes and extends until the arm, on which a cross member is situated receives the end of the said screw spindle.
The lower end of the arm rotates on the body by means of a pin, and its upper end includes a holder plate on which the edge of the vehicle body is supported.
In certain solutions for jacks of this type, the cross member and the holder plate can consist of one single part.
2. Prior Art
Though patent EP-A-0332565 a jack is known which is provided with a base plate for support on the ground and provided with facing side elevations with holes, in the shape of inwardly protruding necks, into which facing holes made in the wings of the U-shaped section of the body or leg fit, so that the necks of the base body are received in the holes in the body, performing the function of the mutual rotation axis between both parts.
In the same way, through this document, the existence is known of two raised stops in the centre of the base plate, one of which acts to provide an inclination to the body at the start of raising, while the aim of the other is to limit the inclination of the body in the maximum elevation of the jack.
In an almost similar manner to the provision of the holes and necks in the body and in the base plate, as has been described, document EP-A-0621230 carries out this same function based on altering the arrangement of the two items, i.e. some facing protruding bodies on the wings or sides of the body and two facing holes in the elevations on the base plate.
These known techniques have the disadvantage arising from the assembly between the body and the base plate, which means the application of a series of operations that make the assembly process more costly, and on which the formal constitution of the base plate itself has an influence, as will be explained later.
With regard to the nuts, units are known which are formally established by some cylindrical elements provided with a central area of greater diameter and with a hole for the screw spindle to pass though and continue to the start of the winding handle, on whose sides annular slots are established in order to receive the thickness of the wings of the body, with some outer ends of greater diameter which are supported on the outer surfaces of the said wings. These nuts, already known in themselves, are fixed to the body, once inserted, by various means, usually bothersome and involving a certain amount of complication in assembly.
Through document EP-A-0683130, for example, a holder plate is known that receives the thickness of a protuberance on the body of the vehicle in a recess with which it is provided, with this holder plate being situated at the free end of the jack arm and housed by means of recesses made in the wings of the U-shape of which the said arm is formed. This holder plate is provided with some annular slots close to its longitudinal ends, in which the thicknesses of the arm are received, and its rotation in the recess in the said arm is limited by some outer prongs that it is provided with.
In general, these holder plates are usually assembled in a complicated manner in the recesses in the arm, given that they usually turn in order to provide their entry and then turn again for their final emplacement.
Also known through EP-A-01636571 is a cross member that takes in the end of the screw spindle through some washers and a ball cage. In this reference, an item prior to the washer and ball cage is controlled in its position by means of two side lugs protruding from the sides of some widenings of the arm, which are bent after the arrangement of the said prior item or cross member.
The disadvantages of this arrangement lie in its arduous assembly and the relative resistance of the cross member itself
Also known, through document EP-A-0697365, is a holder plate-cross member that carries out the double function of taking in the end of the threaded screw spindle and, moreover, receiving the bodywork of the vehicle. The end washers and ball cage are included in a closed housing at the outer end of the holder plate-cross member.
In some cases, these holder plate-cross members are made of metal, with the disadvantages of their excessive rigidity, a considerable cost and an assembly also of a certain importance, as well as their lack of elasticity.
When these holder plates are manufactured in plastic material, the disadvantages that they have consist of complicated assembly and problems of breakage of the seating for the vehicle body.